Remember this about the Iowa caucuses: the delegate outcome is not binary.
Iowa is not a winner-take-all (first-past-the-post) state. Delegates are apportioned according to the vote. Also, complicating things: local caucuses don’t even pick the delegates to the national nominating conventions. The Monday night caucus meeting merely send delegates to county caucuses held later, the county caucuses pick delegates for district level, and finally there’s a state level caucus that sends delegates to the national nominating conventions. Later stages are all but ignored, but often the result will flip on the way up the food chain. In 2012, or example Romney and Santorum were virtually tied at the local level 29,839 to 29,805 with Ron Paul coming in third at 26,036 votes. But at the GOP national convention, the Iowa delegation voted 22 votes Ron Paul and 6 votes for Romney.
There will be huge bragging rights for coming in first on Monday night, but for Democrats, the race looks tight—Nate Silver gives the edge to Clinton—and it will be unlikely that either candidate will run away with it. For Republicans, with Trump and Cruz dominating, the real battle will be for third place.
Republicans are looking for three tickets out of Iowa. Democrats will have only two. Barring a tsunami, both Clinton and Sanders will still be strong and viable candidates moving on to New Hampshire. Governor O’Malley and several of the GOP candidates will be nearly out of runway.